Does a Rogue with Cardsharp (Deadly Dealer) need the Quick Draw feat to keep throwing cards if he is holding the deck of cards if he has more attacks per round?
RAW, they need Quick Draw
*Of some note, the cards are destroyed on use just like thrown ammunition, unlike non-ammunition thrown weapons (such as darts).
Speak with your GM about the deck being "considered" the dart weapon, so as long as you "wield" the deck, you would be able to perform attacks with it. The damage is essentially the same as thrown ammunition options (see halfling sharpstones and throwing arrow) making this a very reasonable ruling.